CVE-2026-67327 — better-auth
CVE-2026-67327 is a Improper Authentication vulnerability in better-auth. A fix is available for better-auth — see the affected versions and patch details below.
better-auth before 1.6.22 Account Takeover via Magic-Link Email-OTP
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-67327.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
better-authnpmDescription
better-auth versions >= 1.1.3 and < 1.6.22 (and pre-release versions >= 1.7.0-beta.0 and < 1.7.0-beta.10) are vulnerable to account takeover via pre-account hijacking on magic-link and email-OTP sign-in when open email/password registration is enabled. An attacker registers an account with the victim's email address and an attacker-chosen password; the account remains unverified. When the legitimate owner later signs in via the magic-link or email-OTP passwordless flow, the account is marked verified without removing the pre-existing password or revoking existing sessions, so the attacker's password remains valid, granting persistent access to the victim's account. Fixed in 1.6.22 and 1.7.0-beta.10.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | better-auth | ≥ 1.1.3&&< 1.6.22 | 1.6.22npm install better-auth@1.6.22 |
| 📦npm | better-auth | ≥ 1.7.0-beta.0&&< 1.7.0-beta.10 | 1.7.0-beta.10npm install better-auth@1.7.0-beta.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for better-auth, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update better-auth to 1.6.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-67327 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-67327 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-67327. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-67327 in your dependencies?
O3 Security finds CVE-2026-67327 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.